Chair construction



y 4, 1968 J. J. GALLA ETAL 3,382,566

CHAIR CONSTRUCTION Original Filed July 2. 1963 United States Patent3,382,566 CHAIR CONSTRUCTIQN Joseph J. Galla and Philip J. Williams,Fairfield, Conn.,

assignors to Stewart-Warner Corporation, Chicago, 111., a corporation ofVirginia Original application July 2, 1963, Ser. No. 292,268.

Divided and this application Feb. 25, 1966, Ser.

2 Claims. (Cl. 29-509) This application is a division of applicationSer. No. 292,268, filed July 2, 1963, and relates to a pedestal-typechain and its construction, and more particularly, to the assembly insuch type of chair of the chair post and chair lron.

A typical pedestal-type chair, such as the stenographic orexecutive-type ofiice chair, commonly includes a chair post connected atits lower end to a chair pedestal and at its upper end to a chair iron,which in turn supports the chair back and the chair seat. Frequently,these components are fabricated by a different manufacturer than theultimate chair manufacturer or seller, so that they must be shipped toand be assembled by the latter to form the completed chair. The chairpost and chair iron are particularly troublesome, since they must beconnected together rigidly and with sufiicient holding capacity tosupport the full load of the chair.

One commonly followed practice in the chair business is that themanufacturer of the chair post and chair iron permanently secures themtogether such as by staking, press-fitting and pinning, or even welding;and ships them as an assembly to the chair manufacturer or seller. Thistype chair post-chair iron assembly generally is economical,structurally sound, and is ready for use in the chair. The assembly hasits disadvantages, however, since being considerably bulkier than thechair post and chair iron separately, it requires larger storing andshipping space; and, being permanently connected, it cannot beinterchanged with various other chair posts or chair irons to givedifferent chair post-chair iron combinations.

An alternative practice is to ship the separated chair post and chairiron to the chair manufacturer or seller, who in turn, secures themtogether. The components being separated until used permit compactshipping and storing. However, since generally special equipment andlabors are required to assemble the components properly, most chairmanumacturers or sellers prefer the first-mentioned practice, even withits disadvantages.

Several designs provide a detachable-type connection between the chairpost and chair iron, such as with a third connection. However, suchdesigns have not been accepted commercially due primarily to theirhigher cost, complicated or lengthy assembly procedures, and lack ofrigidity.

Accordingly, an object of this invention is to provide a chair post andchair iron combination which can be secured together easily and manuallywithout elaborate tools or time consuming labors by the chairmanufacturer, seller, or ultimate user.

Another object of this invention is to provide a chair post and chairiron combination which can be assembled only according to the intendeddesign to minimize wear of or strain on thecomponents, and whichthereafter prevent relative rotation of the components.

Another object of this invention is to provide an improved means for andmethod of forming a fabricating at least part of the structure to effectthe previous object by and upon part of the fabrication of the chairiron itself.

In order that these as well as other objects can be more fullyappreciated, reference is herein made to the following specificationincluding as a part thereof the accompanying drawings, wherein:

FIG. 1 is a side elevational view of a typical executive pedestal-typechair showing the preferred embodiment of the subject invention;

FIG. 2 is an enlarged sectional view of the subject invention as seengenerally from line 22 of FIG. 1;

FIG. 3 is an enlarged elevational View, partially in longitudinal centersection, of the connection shown in FIG. 2.

FIG. 4 is a top plan view of the connection shown in FIG. 3; and

FIG. 5 is a side elevational View, partially in longitudinal centersection, of a typical arrangement of the components and appropriatefabricating tool members before the actual fabrication thereof.

FIG. 1 shows a typical pedestal-type posture chair 10 of the executivetype. The chair 10 includes a chair pedestal 12 supported on floorsurface 13 and in turn supporting vertically a chair post 14 connectedat its upper end to chair iron 16. The chair iron 16 supports the chairseat 1 8 and a chair back 20.

conventionally, the chair iron 16 includes a pair of spaced side members22 (only one of which is shown in FIG. 2) adapted to be connected to theunderside of the chair seat 18. A cross member 24 extends across theunderside of the chair seat 13 and is connected to the opposite sidemembers 22. Resilient spring means, such as torsion bar 26, is connectedto the side members 22 and the cross member 24 in an appropriate mannerto produce the desired resiliency of the chair back or chair seatrelative to the chaid post.

The chair post 14 is connected, as at 28 to the chair iron 16. The chairpost 14, threaded as at 30 and having an axially extending keyway 32, isconnected in an appropriate manner to the chair pedestal 12 to permitheight adjustment of the chair seat 18. A construction of the threadedconnection between the chair post and the chair pedestal can be found inPatent No. 2,999,665, issued Sept. 12, 1961, to S. A. Erickson et al.entitled Locking Arrangement for Swivel Chair Structure.

The chair 10 shown is an executive-type chair wherein the chair back 20is fixed relative to the chair seat 18. Details of construction of thechair iron 16 shown can be found in Patent No. 2,971,569, issued Feb.14, 1961, to H. W. Parrott et al. entitled Tiltable Ofiice Chair. Chairirons, however, can also support the chair back tiltably relative to thechair seat as is shown in Patent No. 2,374,350, issued Apr. 24, 1945, toW. F. Herold entitled Posture Chair. Accordingly, it should beunderstood that the particular improvement to be disclosed herein hasapplication to any type chair post-chair iron combination.

FIGS. 2, 3 and 4 show the connection 28 including the cooperation of itsvarious components. The cross member 24 of the chair iron 16 has anopening 34 that receives a post support member 36. The post supportmember 36 has an intermediate shoulder 37 which bears against the lowerside of cross member 24 to support the load of the chair. A washerelement 38 is between the cross member 24 and a flattened or flaredoverportion 39 on the post support member 36. The post support member 36is thus confined rigidly to the cross member 24.

The post support member 36 is annular having a conical through-bore 4t}tapered uniformly along its length to its largest cross-dimensionadjacent the chair pedestal 12. A raised key portion 42 extends axiallyof the through-bore 3 40. The chair post 14 is tapered at its upper end44 to an identical conical taper angle as the through-bore 40 and isadapted to fit complementally therein. Thus, the tapered end 44 of thepost 14 is larger adjacent the chair pedestal 12 than adjacent the chairseat 18.

The conical tapers 4t and 44 are tapered at a small taper angle relativeto their longitudinal center axes and engage one another oncomplementary axially extending surfaces. The tapers are thusself-locking or self-holding with one another. The basic requirement ofa self-locking taper is that the taper causes a greater frictional forcecomponent in the direction parallel to the engaging surfaces than theforce component tending to separate them. Conventionally, a self-lockingtaper has a taper angle varying from approximately /2" to per foot. See,for example, the Morse, the Brown and Sharp, the Jarno and the AmericanStandard Machine tapers.

The chair post and the chair iron are secured together solely by meansof the frictional forces developed between the complementary engagingsurfaces on the selflocking tapers 40 and 44. The key portion 42 on thepost support member 36 cooperates with keyway 32 on the chair post 14 toprevent rotation of the chair iron on the chair post. Also, since thiscooperation occurs in only one rotatable position of the chair post andchair iron, by properly locating the key portion 42 relative to thechair iron, strains can be minimized. For example, when key 42 is inalignment with the axis of tilt of the chair seat, as shown, any diggingof the pointed edges of the keyway 32 into the bearing (not shown) inthe pedestal 12 upon a user swivelling in the chair is minimized. Theintegral key portion 42 readily locates this proper position even forin-the-field assembly.

It should be noted that self-locking tapers can be separated from oneanother without too much difliculty by impact-type blow tending todislodge them. Thus, the top portion of the chair post, as at 47,projects slightly beyond the chair iron when assembled thereto so that ahammer (not shown) can be directed against it to separate the chair postand chair iron.

Also of particular significance in the subject invention is the mannerin which the key portion 42 is formed in the bore 40 of the post supportmember 36. It can be noted in FIG. that before the post support member36 is secured to the chair iron, it has extending from the shoulder 37 atubular shank 52 of exterior size comparable to opening 34 of crossmember 24. The exterior of the shank 52 is knurled at 54 adjacent theshoulder 37. The shank is adapted to be press-fit into the opening 34from the pedestal side of the cross member 24 until the shoulder 37abuts the cross member 24. Washer 38 having an intermediate opening 55also fits over the shank 52 and abuts the cross member 24 On the sidethereof remote from the shoulder 37. It is contemplated that the flare39 is formed by staking it over the frame member and washer. For thispurpose it is desirable that the washer 38 be of a harder materialtowithstand the staking operation without deforming.

FIG. 5 also shows a preferred tool arrangement for staking the postsupport members 36 to the chair iron 16 and for forming the key portion42. The washer 38 is placed in a recess 58 on a frame or tool table 60,and the cross member 24 is placed over the washer 38 onto the tool table60. The shank end 52 of the post support member 36 is inserted into theopenings 34 and 55 and pressfit by means of tool 62 into the crossmember 24 until the shoulder 37 abuts the cross member. In this insertedposition, the shank 52 projects past the Washer 38 into a bore 64 withinthe frame or tool table 60 which houses a second tool member 66. Theadvance relative to the first tool member 62 of the second tool member66 against the projected end of shank 52 causes the end to be stakedover the washer 38 as at flare 39 (FIG. 3). The second tool member 66has an inner bore 68 which partially encloses the projected end 69 ofthe shank 52 to cause the staking or flare 39 to occur more readily.

The first tool 62 is tapered at 70 to an identical taper angle as bore40 of the post support member 36 and the taper 44 on the chair post 14.The exterior surface of the tapered tool 62 has therein an axiallyextended keyway 72 which is of general size and dimension as the keyway32 of the chair post 14. Upon staking of the post support member 36 tothe chair iron -16 by and upon the advance of the tool members 62 and 66toward one another, the unsupported portion of the post support member36 over the keyway 72 is deformed into the keyway. This causes thepreviously-mentioned axially extended out-of-round key portion 42 on thepost support member 36. It is to be understood that the tool members 62and 66 are of sufficiently hardened material to avoid flowing during thestaking operation. After the staking operation the tool members 62 and66 are withdrawn, and the components removed from the tool table 60.

Thus, the key portion 42 is formed simultaneously with the staking ofthe post support member 36 to the chair iron, and is formed bydistorting the normal symmetrical dimension of the through-bore 40 intothe through-bore. The integral keyway 32 and key portion 42 preclude theloss of otherwise separate locking components which would render theconnection less efiicient.

It has been determined that tapers of .6" per foot taper fromapproximately 4" larger cross-dimensions mating along axial lengths of 1/2 give sufiicient holding power to secure a typical chair post-chairiron combination. A key portion raised a minimum of .005 has been foundsufiicient to ensure proper positioning of the components together andto prevent rotation of them relative to oneanother.

While only a single embodiment of the subject invention has beendisclosed, it will be obvious to those skilled in the art that variousother designs are possible. Accordingly, it is desired that theinvention be limited only by the scope of the claims hereinafterfollowing.

What is claimed is:

1. In combination with a chair post and a chair iron, an improvedconnection of securing them together formed by the steps of positioningan annular post support member through an opening in a cross member ofthe chair iron to project from both sides of the cross member, ofstaking the post support member to the cross member by means including afirst tool member having its exterior surface converging conicallytoward its end at a small angle self-locking taper and having therein anaxially formed keyway positioned within a complementary tapered althoughuniformly conical opening in the post sup port member and a second toolmember on the opposite side of the cross member by and upon advancingthe first and second tool members toward one another, effective therebyalso to force at least a portion of the post support member disposedover the keyway of the first tool member into the key to cause anaxially extending key portion raised from the periphery of the taperedbore of the post support member, and of removing both the first andsecond tool members from the chair iron, whereby a chair post memberhaving a tapered end and axial keyway similar to the first tool membercan subsequently be positioned into the bore of the post support memberin proper rotational alignment with the key portion thereof and bedriven against the post support member, effective thereby by means ofthe self-locking tapers of the members to secure them axially andnon-rotatably together.

2;. The method of fabricating a planar chair iron cross member toprovide a self-locking tapered surface thereon together with key means,the improvement comprising the steps of placing a post support memberhaving a tapered bore into an aperture in said cross member, moving afirst tool having an identical taper to said bore into said bore whileforcing said member through said aperture until a shoulder on saidsupport member engages said cross member adjacent one side of saidaperture with said support member projecting through said aperture,moving a staking tool against the projecting end of said support memberto stake said projecting end over said planar chair iron cross member toprevent disengagement of said support member from said cross memberwhile said first tool is engaged in said bore, and the step ofsimultaneously forming a key in the surface of said bore during thestaking of said projecting end.

References Cited UNITED STATES PATENTS Herold 297-301 Lathrop 29-469 XHitt 28753 Hild et a1. 29509 OTHELL M. SIMPSON, Primary Examiner. 10 A.WEIDENFELD, Assistant Examiner.

2. THE METHOD OF FABRICATING A PLANAR CHAIR IRON CROSS MEMBER TO PROVIDEA SELF-LOCKING TAPERED SURFACE THEREON TOGETHER WITH KEY MEANS, THEIMPROVEMENT COMPRISING THE STEPS OF PLACING A POST SUPPORT MEMBER HAVINGA TAPERED BORE INTO AN APERTURE IN SAID CROSS MEMBER, MOVING A FIRSTTOOL HAVING AN IDENTICAL TAPER TO SAID BORE INTO SAID BORE WHILE FORCINGSAID MEMBER THROUGH SAID APERATURE UNTIL A SHOULDER ON SAID SUPPORTMEMBER ENGAGES SAID CROSS MEMBER ADJACENT ONE SIDE OF SAID APERATUREWITH SAID SUPPORT MEMBER PROJECTING THROUGH SAID APERATURE, MOVING ASTAKING TOOL AGAINST THE PROJECTING END OF SAID SUP-